Correct Fluids for 1978 Cheorkee

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nograin
Posts: 26
Joined: Thu Nov 09, 2017 7:37 am
Location: Phila. Pa
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Re: Correct Fluids for 1978 Cheorkee

Post by nograin »

I think you guys summed it up well.
20W-40 and 10W are the only two that are now rare birds and there's really no reason to use either with the other choices available.

I basically agree with the need for zinc phosphorus additives for our engines. It was a well proven approach that worked well with all flat lifters, whether they were hydraulic or solid. I'm not against other approaches, but prefer to stick with the known for my own stuff. The SAE papers cited (but I haven't read myself) indicate oils with around 800 ppm will do the job well. With high lift cams and associated higher spring pressures, more zinc provides a little more insurance the zinc/phos will continue to have adequate levels before the next oil change. These additives do contribute to some contaminent formation, which contributes to wear, so there's no reason to go crazy with the stuff. Also somewhere above 1400 ppm, they can actually contribute to surface damage.

Fast Eddie
Posts: 53
Joined: Thu Nov 30, 2017 8:18 pm
Location: South Lyon, MI

Re: Correct Fluids for 1978 Cheorkee

Post by Fast Eddie »

Sorry guys! I should of stated "some of the oils" are NOT as available as others...!!!

Thanks for added info on the ZINC/Phos additives!! I know the PO gave me some to add at oil changes. Good INFO!! Much appreciated!
1979 J20, 360 w/NV4500/D300 Twin Stick/3.73 SOLD
1978 Cherokee Chief W/T Levi interior, 360 Q/T. SCRAPPED
1970 Gladiator J4800 Camper Special, Buick 350, 4spd. SOLD
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